The present invention relates in general to film viewing and more particularly concerns novel apparatus and techniques for providing photo interpreters with the means to view imagery using diffuse and specular illumination in a relatively compact structure that facilitates selection of conventional diffuse illumination or specular illumination for image enhancement.
Typically photo interpreters view films on a light table having diffuse illumination. However, specular illumination provides image enhancement. One prior art approach for providing specular illumination of spots on a diffuse background used a specular source above a diffuse source with both being below clear glass. This arrangement is characterized by a number of disadvantages. The structure is bulky, and it is difficult to view a transparency spaced from the diffuser plate.
Accordingly, it is an important object of this invention to provide an improved stereo light table providing photo interpreters with the means to view imagery using diffuse and specular illumination.
It is a further object of the invention to achieve the preceding object while eliminating one or more of the disadvantages noted above.
It is a further object of the invention to achieve one or more of the preceding objects with a compact arrangement that provides a convenient means for controlling the illumination.
It is another object of the invention to achieve one or more of the preceding objects while controlling brightness of the specular source independently of color temperature.
It is a further object of the invention to achieve one or more of the preceding objects while controlling the range of illumination type at spots on the light table between specular and diffuse.
It is a further object of the invention to achieve one or more of the preceding objects with a compact light table arranged for viewing stereo images.